Interaction with computing devices is a fundamental act in today's world. Computing devices, such as personal computers, tablets, smartphones, are found throughout daily life. In addition, computing devices that are wearable, such as wearable headset devices (e.g., virtual reality headsets and augmented reality headsets), are becoming increasingly popular. The systems and methods for interacting with such devices define how they are used and what they are used for.
Advances in eye tracking technology have made it possible to interact with a computing device using a person's gaze information. In other words, the location on a display the user is gazing at. This information can be used for interaction solely, or in combination with a contact-based interaction technique (e.g., using a user input device, such as a keyboard, a mouse, a touch screen, or another input/output interface).
Previously proposed interaction techniques using gaze information can be found in U.S. Pat. No. 6,204,828, United States Patent Application Publication 20130169560, U.S. Pat. No. 7,113,170, United States Patent Application Publication 20140247232, and U.S. Pat. No. 9,619,020. The full specification of these patents and applications are herein incorporated by reference.
In order to ensure that a target of the user gaze is accurately inferred from observations of the user's eye, calibration of an eye model, such as a deep learning-based model or pupil center cornea reflection (PCCR) model, is necessary. Note that the terms “eye model” and “personal calibration parameters” will be used herein to refer to parameters to calibrate eye tracking systems, where these parameters can be personalized to a user of the eye tracking system. This can include an eye model such as PCCR, a machine learning or deep learning system, or another model.
For example, a 5-, 7-, or 9-point pattern can be used to obtain a thorough calibration of personal calibration parameters, such as pupil and foveal offset. However, over time, the personal calibration parameters generated from such an initial calibration become less applicable as the user's eye changes (e.g., pupil size changes) due to changes in lighting, eye fatigue, etc. For example, a pupil offset can change when the pupil size changes, and the cornea shape shifts throughout the day.
As a result, the gaze computed based on existing calibration parameters becomes progressively less accurate, and the model requires recalibration. One method to correct for this is to prompt the user to do a complimentary manual calibration, similar to the initial calibration. However, this is inconvenient and disruptive for the user, as other applications must be interrupted while a full multi-point calibration process is performed.